JPS5861600A - X-ray diagnostic equipment - Google Patents

Abstract

PURPOSE:To observe inviariably stable monitor images by automatically setting the incidence light quantity into a camera tube properly in accordance with diagnostic conditions so as to control the luminance of a television monitor. CONSTITUTION:An X-ray control unit 1 controls an X-ray generator 2 and also outputs selected signals in accordance with diagnostic conditions (perspective mode, photographing mode, etc.). When receiving these signals, a lens diaphragm control circuit 18 controls a lens diaphragm 11 provided in an optical system 10 through a drive circuit 19. As a result, the incidence light quantity from an X-ray-light image conversion unit 9 into a camera tube 13 is automatically set at a proper value in accordance with diagnostic conditions. Therefore, the images on a television monitor monitoring the X-ray images on the camera tube 13 are set at the proper luminance, thus invariably stable monitor images can be observed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an X-ray diagnostic apparatus, and more particularly to an X6 diagnostic apparatus having a function of always optimizing the brightness of the monitor regardless of changes in various diagnostic conditions.

Most X-ray diagnostic equipment performs X-ray fluoroscopy and X-ray photography for the purpose of dynamic diagnosis of subjects such as patients and positioning during imaging. Examples include those shown in Figure 1. In this case, the high ridge pressure generator 2 is controlled by the radiation controller 1 to emit X-rays from the XfIii tube 3, and at this time, the X-rays transmitted through the subject 6 placed on the top plate 5 are converted into light gI! Convert to X4! - A light image converting device, for example, Image Inten 7 Fire (hereinafter abbreviated as I@I) 9 converts it into a light image, and images it with a television camera 14 via a tomogo optical system 10, and displays it on a display device, for example, a TV. Display the image on the monitor 15 and perform fluoroscopy (1 step; for direct imaging, insert the X-ray film 8 of the spot device 7 and take the image; for indirect imaging, use the objective lens 12A and condenser lens 12B) A half-mirror 16 is placed in the middle of the lens to let in a portion of the light, and an indirect camera 17 is used to take pictures.

Generally, the fluoroscopy conditions are an X-ray tube voltage of 50 to 120, for example.
For example, the X-ray tube current is 0 to 4, and the time is continuous. On the other hand, the X-ray tube voltage under direct imaging conditions is approximately the same as that for fluoroscopy, for example, 70 to 120 KV, and the X-ray tube current is, for example, 100 to 3
00mA, which is approximately 100 times that during fluoroscopy, and the imaging time is 0.
01 to 0.1 seconds. Therefore, the incident X-ray dose per unit time is much higher during radiography than during fluoroscopy. If shooting is required for a short period of time, it will become thinner. Even considering the X-ray absorption of the close contact device, which consists of an intensifying screen and film that are inserted between subject 6 and l-l9 only during imaging, it can be seen from a simple measurement that it is extremely high compared to fluoroscopy. . This extreme difference in the amount of light incident on the I/II9 directly appears as a difference in the amount of light incident on the television camera.

In general VXfs fluoroscopy, the aperture diameter of the lens diaphragm 11 that controls the amount of light input to the X-ray television camera is set in advance to be appropriate during fluoroscopy in order to continuously view the X-ray television monitor directly. Therefore, in a conventional device equipped with a lens diaphragm that cannot change the diaphragm diameter, the TV monitor 1
While a clear X-ray image is displayed on the television monitor 15, an extremely high level video signal is output at the moment of imaging, causing halation in the X-ray image on the television monitor 15, resulting in the following drawbacks.

(1) Extremely excessive scenes are incident on the television camera, leading to deterioration of the characteristics of the television camera and shortening of its service life.

(2) Halation occurs instantaneously when viewing a television monitor image with appropriate brightness during fluoroscopy, which has negative physical and psychological effects on the observer, such as eye fatigue.

(3) Due to the halation that occurs at the moment of imaging, it becomes difficult to recognize the monitor image, such as the position of the contrast agent during imaging. (4) If an excessive amount of light enters, the amount of input light may decrease due to the falling characteristics of the TV camera. Even when it stops, the output signal does not fall immediately and remains as an afterimage for a long time. Therefore, even if the condition is returned to the fluoroscopic condition immediately after photographing, a clear fluoroscopic image cannot be obtained due to the afterimage O.

Similar problems occur in indirect photography because a larger amount of X-rays is required than in fluoroscopy. Also, dual mode ■・
Multiple input field of view switching such as I (DUAL MODE I, I), TRIPLE MODE I (TRIPLE MODE I@I) - In the case of IOX X-ray diagnostic equipment, the output for the incident X-ray dose can be changed depending on each set field of view mode. Since the brightness is different, the output brightness will further vary depending on the combination of the above-mentioned fluoroscopy, direct photography, and indirect photography conditions.

In this case, the lens diaphragm can be controlled by a conventional mechanical mask, or the lens diaphragm can be controlled to an arbitrary value as proposed in Japanese Utility Model Publication No. 48-14421, but only one aperture value can be set. ], it is difficult to properly control the amount of light incident on the diversified television cameras.

The present invention has been made to solve the above-mentioned problems, and provides an X-ray diagnostic device equipped with an optical aperture function that can automatically set the amount of light incident on a television camera appropriately according to the purpose of use. The purpose is to

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. FIG. 2 is a block diagram showing the configuration of the device according to the present invention. In the diagram, the same parts as in FIG. In order to achieve this, a lens diaphragm drive circuit 19 that controls the diameter of the lens diaphragm 11 disposed in front of the condensing lens 12B in the optical system 10 and a lens diaphragm control circuit 18 that controls this drive circuit 19 are provided. The control circuit 18 is controlled by a signal SM based on the mode selection from the X-ray controller 1 and a mechanical/engineering input visual field selection signal S.

Next, the specific configurations of the lens diaphragm control circuit 18 and the lens diaphragm drive circuit 19 will be explained.

FIG. 3 is a detailed circuit diagram of the lens diaphragm control circuit 18 and the lens diaphragm drive circuit 19. The lens diaphragm control circuit 18 includes a control signal generating section 18A, an initial setting section 18B,
It is configured by a multiplication section 18C. First, the control signal generating section 18A generates seven various mode signals from the X@controller 1, that is, a fluoroscopy mode signal SMov direct imaging mode signal 8M! (a) Indirect photography mode signal SMx;
20 input visual field selection signal S 8. A third input visual field selection signal S-3 is input. Of these, the first input visual field selection signal SII and the fluoroscopy mode signal SM are configured not to be actively used. That is, the second and sixth input visual field selection signals SIN a SIN and the direct imaging mode signal SM
1 and indirect photography mode signal SMs are respectively input to the correspondingly arranged first to fourth inverters IN, to IN4K, and among these, the first and M2 inverters INI m INK
The output of the first and second NAND gates NAND1. NA
ND, and outputs of the third and fourth inverters INs-IN4 to the sixth NAND gate NAND.

02 Apply as human power, this Nantes gate NA? 1a)
s and the direct photographing mode signal SMs, an ORs k is provided, and the output of the OR gate ORt is connected to the output of the OR gate ORt. It is commonly applied to the other inputs of the second NAND gates NAND1 and NANDt, and the first... 2nd Nandogoo) NANDt, NA
4th Nantes gate handling m that requires two people to output NDx
The output of ORt is inverted by the fifth inverter INs to obtain the first control signal s1, and the sixth inverter INs obtains the second control signal S:. The output of NANDs is inverted by the sixth inverter IN, and the third control signal Ss? obtained, the fourth NAND gate NAND4 is inverted by a seventh inverter IN to obtain a fourth control signal 84, and the fourth control signal 84 is obtained. Second Nant gate NAND1. NAND2t each 8th. The fifth inverter is inverted by the ninth inverter INs-IN. The sixth control signals Ss and S@ are obtained.

The initial setting section 18B has an operational amplifier (hereinafter also referred to as an operational amplifier) At, which inputs the divided voltage output of the voltage dividing resistor Rt-& to an inverting input terminal via a resistor Rst, and whose non-inverting input terminal is grounded. , a variable resistor ■1~VR, and an analog switch ASI are connected between the input and output terminals of this operational amplifier AI.
- ASs are combined and connected in series for each corresponding code, and six series circuits are connected in parallel.

Note that each analog switch ASl to Asm is, for example, Fli
The traps are controlled by the first to third control signals St to 81 from the control signal generating section 18A, respectively. Here, the variable resistor VRt −VR
The values of s are set to be different in sequence.

The multiplier 18C has an operational amplifier Ast- which inputs the output of the operational amplifier A of the initial setting unit 18B to an inverting input terminal via a resistor Rat, and whose non-inverting input terminal is grounded. Variable resistance VR between terminals
, ~vR6 and analog switches A84 to ASat are connected in parallel, and three series circuits are connected in series in combination for each corresponding code.

Each of the analog switches As4 to As· is, for example, an FIT, and the control signals 84 to 84 from the control signal generator 18A are
It is controlled by S. Here, the variable resistors VR4 to VRs are set to have different values in sequence.

So, do you select perspective mode when you are in visual mode? ,(
The signal SMo is generated, but since this signal is not actively used, only the first control signal S1 is output from the control signal generating section 18A, and the signal SMo is output between the input and output terminals of the operational amplifier A1 in the initial setting section 18B. When the first analog switch ASft of the connected series circuits is closed, the calculation result output with the amplification factor determined by the variable resistor VRI and the resistor R3 is output and input to the multiplier 18C. Become. Hereinafter, during direct photography, the direct photography mode signal SMI is input and the second control signal Ss is generated, so only the analog switch A82 is closed, and the calculation result is output with an amplification factor based on it, and during indirect photography, the third control signal SMI is input. control signal S
s is output, only the third analog switch AS is closed, and the calculation result output with the amplification factor based on it is obtained. Then, in the multiplication section, when the first input field of view of ■•I is selected, the first input field of view selection signal Sx!
is output, but this signal is not actively used, and only the fourth control signal S4 is output from the control signal generator 18A. Analog switches AS4 to AS connected between the input and output terminals of the operational amplifier Am in the multiplication section 18C.
6, only the fourth analog switch AS4 is closed, and the output from the initial setting section 18B is multiplied by the amplification factor determined by the variable resistor vR4 when the analog switch Ahm is closed, and the multiplication result is output. be done. Similarly, when the second I/■ input field of view is selected, the input field of view selection signal Sl3 is output, and based on this, the control signal Ss of wJ5 is generated, and only the fifth analog switch Asm in the multiplier 18C is closed and the same multiplication as described above is performed, and when the sixth I-I input field of view is selected, the corresponding signal Sxs is applied, and a sixth control signal S6 is generated,
Sixth analog switch AS.

is closed and the same multiplication as described above is performed.
, a drive circuit 19B that generates a drive signal based on the output of this amplifier 19A, and a galvanometer 1 that is driven by this drive circuit 19BK to control the aperture diameter of the lens aperture.
9C, an aperture diameter detector 19D that detects the amount of rotation of the rotational pre-excitation of the galvanometer, and an amplifier 19E that amplifies the output of the aperture diameter detector 19D.
9 is applied to the other input terminal of the error amplifier 19A. Therefore, a comparison is made between the aperture diameter setting signal inputted by the error amplifier 19A and the actually set aperture diameter detection signal (output of the multiplier iiM unit 19E).
The galvanometer 19C is driven until the two match, and automatic adjustment is performed to obtain the optimum aperture diameter.

Next, the operation of the apparatus having the above configuration will be explained.

First, considering the case of fluoroscopy, the X emitted from the Xm tube 3
The line is x@shibori! 14. Top plate 5. Transparent through subject 6
OI incident on 9! In step 9, incident X-rays are first converted into electrons, and the electrons are converted into light and output. The output light from the lens 9 is guided to the image pickup tube 13 by the objective lens 12A and the condenser lens 128.

A video signal from the image pickup tube 13 is sent to a television monitor 15 and displayed as an X-ray fluoroscopic image. At this time, the X@controller 1 outputs the fluoroscopy mode signal SM. However, the lens diaphragm control circuit 18 in FIG. 3 directly outputs the indirect photography mode signal SMI # SM! Since both of them are at the "H" level, only the output of the fifth inverter IN, that is, the first control signal St, is at the "H" level, and only the first analog switch AEt is closed. A
From I, the input voltage is multiplied by the voltage across the terminals of the first variable resistor (1) to generate a specific output. At this time, if the first input visual field is selected among the input visual fields of the Hiro 4 input visual field, only the first input visual field selection signal S is outputted, so the control signal generator 18A outputs the input visual field of the Hiro 4 The control signal S4 is output, the fourth analog switch AS4 in the multiplication section 18C is selected, and the output signal from the initial setting section 18B is multiplied by the amplification factor determined by the variable resistance foil and the input resistance R4, and the resultant signal is output. Ru. Similarly, when the second and third input fields of view are selected, each selection signal is output.

S'I3 is output, and the 5th. Sixth control signal 5s-8-
are output, and each analog switch As
s and Asm are selected, an output signal multiplied by the amplification factor at that time is output from the multiplier 18C. The lens aperture drive circuit 19 sets the aperture diameter of the lens aperture to an appropriate value based on the output signal from the lens aperture control circuit 18. That is, the error amplifier 19A compares the current aperture diameter detection signal (output of the aperture diameter detector 19D), the amplified signal (output of the amplifier 19H), and the output signal from the operational amplifier A, and calculates the difference between the two. A corresponding output is applied to the drive circuit 19B, and the galvanometer 19C is driven by the output of the drive circuit 19B at this time, and the rotor No. is rotated to adjust the diameter of the lens aperture. The aperture diameter at this time is the detector 19
D is detected, and the detection output is input to the error amplifier 19A via the amplifier 19Et for comparison. The aperture is set to the appropriate aperture diameter.

Next, the operation in shooting mode will be explained. in this case,
X was waiting in a position where it would not receive the shadow of X-rays during fluoroscopy.
Both direct imaging, in which the radiation film 8 moves into the X-ray flux and is exposed to X-rays, and indirect imaging, in which all imaging is performed with an indirect camera via the No.--7 mirror 161 arranged in the optical system 10, are conceivable. . In direct shooting, the input of the third IN/(-TAEN HATA is at the rLJ level, and the input of the fourth IN4 is at the rHJ level.
In the figure, the second control signal Sl is generated in the throttle control circuit 18, and the second analog switch As! (7) The door closes,
Variable resistor ■3 is selected. In the case of indirect photography, a third control signal Sm is generated in which the input of the third inverter INs is at the rHJ level and the input of the fourth inverter IN4 is at the rLJ level, and only the third analog switch Asm is activated. Closed, variable resistor 1 is selected.

Variable resistance 'IEL2 selected by each shooting mode
The amplification degree of the operational amplifier AI is determined by #■1, and the output of the operational amplifier A thus obtained is input to the next stage operational amplifier A via the resistor Rat. As mentioned above, this operational amplifier A3 performs correction based on the selection of the I/I input field of view. 1 and 2nd inverter IN3 # INz
Since both inputs are at the "H" level, only the analog switch AS4 in the operational amplifier A is closed, and the variable resistor V
This means that R4 has been selected. Similarly, when the engineering/engineering input field of view is the second input field of view, the input of the inverter IN is rLJ.
Since the input of the inverter IN is at the rHJ level, only the analog switch ASl is turned on and the variable resistor VR,
is selected, and when the input field of view is the 6th input field of view, the input of the inverter INI is at the rHJ level and the inverter IN
! Since the input of is at rLJ level, analog switch A
Only S6 is turned on, and variable resistor ■. is selected. The amplification factor of the operational amplifier Ax is determined by the VB2 #■ glue or VRs K selected by each input field of view, and the output of the operational amplifier AI is multiplied by the amplification factor by the operational amplifier A and output, and the lens diaphragm drive circuit is operated in the same manner as described above. 19, and automatic control is performed to obtain an appropriate aperture diameter. In this way, an appropriate amount of light is always input to the imaging tube (television camera), and accordingly, the brightness of the TV monitor is also maintained at an appropriate level.

Note that in the above operation, without any particular limitation, the amount of light incident on the image pickup tube in the photographing mode increases significantly compared to that in the fluoroscopy mode, so in order to reduce this, the diameter of the lens diaphragm υ can be adjusted. controlled to be significantly smaller, and
This kind of control is possible because the amount of incident light changes between direct photography and indirect photography, even if the shooting is the same.The diameter of the lens diaphragm is controlled to change accordingly. Said op amp eight! The value of each variable resistor VRI to VRs that sets the amplification factor of Therefore, the values of the variable resistors VR4~■- of the operational amplifier A snow are set to correspond to this and to provide an aperture diameter that allows an appropriate amount of light to be obtained according to the level of the output of the operational amplifier AI. Needless to say, there is nothing to say.

The present invention is not limited to the embodiments described above, and various modifications are possible. For example, in the above embodiment, as a parameter for adjusting the aperture diameter of the lens diaphragm, the case where the input fields of view of I and I were different was considered, but this is especially important when the manual field of view of I and I is constant. In that case, the multiplier 18C in the lens aperture control circuit 18 and the control signal used in its path become unnecessary. In addition, a galvanometer and a rotor were used to drive the lens diaphragm, but this was done to speed up the opening/closing operation of the diaphragm and make it more compact, so it is not necessarily limited to these as long as it achieves the same function and purpose. It is not something that will be done.

According to the present invention described in detail above, the main cover input to the image pickup tube is automatically set to be always appropriate under all diagnostic conditions (particularly fluoroscopy mode and imaging mode), and as a result, the Since the brightness is appropriate, all of the above-mentioned conventional drawbacks are eliminated.

[Brief explanation of drawings]

Fig. 1 is a system block diagram showing an example of a conventional device, Fig. 2 is a system block diagram showing an embodiment of the present invention, and Fig. 3 is a lens aperture control circuit and a lens aperture drive circuit in an embodiment of the present invention. FIG. 2 is a circuit diagram showing an example of a specific configuration. 1.-X-ray controller, 2... X-ray generator, 3...
X-ray tube, 6--object, 7--spot device,
8...X, lI film, 9...X@-Kouwei conversion device, 10...optical system, 11...lens aperture]
, 16... image pickup tube, 15... monitor, 1
7-... Indirect camera, 18... Lens aperture control circuit,
19... Lens aperture drive circuit 0'

Claims (3)

[Claims] (1) XAI by setting diagnostic conditions such as fluoroscopy or imaging
An X1B controller that controls the Xls intensity of emitted X-rays from the tube, an X-ray-light image converter that converts the XM transmitted through the subject into a light image, and a light image from the X-ray-light image converter. In an X-ray diagnostic device that has an optical system that guides the tube, and a display device that displays an X-ray fluoroscopic image based on the output from the imaging tube, and that transmits X-rays during direct or indirect photography. ,
A lens diaphragm that can continuously adjust the diameter of the diaphragm 9 by a drive circuit is provided in the optical system, and a lens diaphragm control circuit that controls the drive circuit is provided, and this lens diaphragm 9 control circuit is controlled by the X-ray control circuit. 1. An X-ray diagnostic apparatus, characterized in that a lens aperture (nt-) is adjusted so that the amount of light incident on the imaging tube becomes appropriate by controlling it with selection signals of various diagnostic conditions from the X-ray diagnostic apparatus. (2) The lens diaphragm 9 control circuit includes at least the XI
8. The X-ray system according to claim 1, wherein lens aperture control signals having different values are generated in response to a fluoroscopy mode signal and a direct imaging mode signal or an indirect imaging mode signal output from the controller. Diagnostic device〇 (3) The X-ray diagnostic apparatus according to claim 2, wherein the lens aperture drive circuit has a galvanometer that operates the lens aperture bt based on the lens aperture control signal.